1. Field of the Invention
The invention relates to a brake shoe, and, more particularly, to a brake shoe assembly with a brake shoe pad which is rapidly and easily removed and replaced.
Through normal use, a brake shoe pad may become worn, affecting the braking of a vehicle and requiring replacement. A traditional brake shoe pad for brake shoes typically is a relatively permanent attachment to the brake shoes. Such traditional brake shoe pads are not easily replaced.
Nevertheless, ease and speed of replacement is generally desirable, in that this tends to reduce the time required for brake maintenance or scheduled vehicle maintenance. Moreover, in some situations, it may be desirable to rapidly replace the brake shoe pads without delaying for scheduled maintenance.
2. Discussion of the Related Art
If faced with replacement of a conventional brake shoe assembly, commercial drivers are confronted with several hours of downtime and greater expenses in parts and labor. Also, food and lodging must be taken into consideration during downtime. Moreover, if the driver is checked at Department of Transportation check points and found to be running with insufficient brake shoe pads, substantial fines are levied against him. A driver cannot continue with trip until replacement brake shoes are installed which takes hours. Downtime for brake shoe assembly repair costs money and expenses.
Many accidents and injuries are caused by not replacing brake shoes when actually needed. Moreover, brake systems occasionally malfunction or lock-up, burning off the brake pads. Several hours of downtime are needed to replace conventional brake shoes. Due to loss of revenue and downtime, many companies and drivers will take the risk of making additional trips before stopping to replace conventional brakes. These actions create hazards on roadways which contribute to highway deaths and accidents.
Additionally, in conventional brake assembly replacement, replacement parts and supplies are needed, for example, seals, axle oil/dope and grease. During replacement, seals are broken releasing axle oils and greases. Grease and oil containers, along with seals and other parts should be disposed of properly. However, this continues to add to land fills, which are already limited in size and capacity. If not handled and disposed of properly, these further contaminate and pollute lakes, rivers, streams and the soil.
One example of a brake shoe mounting assembly is disclosed in U.S. Pat. No. 4,867,285. An arcuate brake shoe confronting a brake drum assembly or an actuator or web assembly is mounted in the housing and engageable with the brake shoe. A slotted beam assembly is attached to either the actuator or the brake shoe, and the insertion assembly is attached to the other. The insertion assembly is fastened within the slotted assembly to lock together the actuator and brake shoe. The slotted and insertion assemblies are released to enable selected removal of the brake shoe from or insertion of the brake shoe into the housing.
One example of a truck brake is disclosed in U.S. Pat. No. 3,398,814. Bolts on the inside of the wheel in alignment with the axle can be removed to free the shoe and its worn lining from the shoe carrier. The lower shoe is removed by a straight axial pole. The upper shoe is unbolted, then turned peripherally to the bottom of the wheel, and similarly removed by a straight axial pole. Hence, the wheels need not be removed for the brakes to receive new linings.
Another example of a brake shoe with replaceable parts is disclosed in U.S. Pat. No. 2,948,360, which shoes a brake shoe including a rim and a web which can be replaced in the field. Additionally, U.S. Pat. Nos. 4,823,921, 4,771,870, 3,467,229 and 3,066,766 disclose brake shoe assemblies with liners which may be removed and/or changed. U.S. Pat. Nos. 4,936,426, 3,941,222, 3,894,620, French Patent 2,003,074 and British Patent 1,264,114 disclose brake shoes with vertical members.
These references teach use of certain elements for various purposes. For example, U.S Pat. No. 4,823,921 teaches the use of rivets to connect brake shoe assemblies. Similarly U.S. Pat. No. 4,867,295 discloses a brake pad with a brake support section including flanges and alignable channel portions. Unfortunately, the brake shoe pads provided thereby have the disadvantage that they are not quickly and easily replaced.
Additionally, some of these brake shoe pads may become loosened during use. Moreover, these brake shoe pads may not be as sturdy as necessary for certain applications.
Thus, there remains a need for an improved brake shoe with a brake shoe pad which can be easily and rapidly replaced. Also, there remains a need for a system which helps the driver to avoid fines and penalties for insufficient brake shoes.
Further, there is a need for a brake shoe system which contributes to a safer, faster and more economical way of moving products on our roadways, along with helping to preserve our resources and protect our environment.